It often happens, and you should email the server owner about this.
If you can, get someone that can write good english, as "y u do dis i dont do wrong" is something most server owners think of as stupidness from the banned botter/scammers side.
Also it could be that you won't get unbanned, because if you do, that botter/scammer will just make new accounts and continue scamming.
Your best choice is to talk to the botter/scammer, and if he says he'll still do it, beat him up or something.